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From: Andrew Morton <akpm@linux-foundation.org>
To: p.jaroszynski@gmail.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
	Christoph Hellwig <hch@lst.de>,
	linux-fsdevel@vger.kernel.org, linux-mm@kvack.org,
	Piotr Jaroszynski <pjaroszynski@nvidia.com>
Subject: Re: [PATCH v2] iomap: get/put the page in iomap_page_create/release()
Date: Mon, 3 Dec 2018 15:22:43 -0800	[thread overview]
Message-ID: <20181203152243.095e6b846fd9f623a339e4ab@linux-foundation.org> (raw)
In-Reply-To: <20181115184140.1388751-1-pjaroszynski@nvidia.com>

On Thu, 15 Nov 2018 10:41:40 -0800 p.jaroszynski@gmail.com wrote:

> migrate_page_move_mapping() expects pages with private data set to have
> a page_count elevated by 1. This is what used to happen for xfs through
> the buffer_heads code before the switch to iomap in commit 82cb14175e7d
> ("xfs: add support for sub-pagesize writeback without buffer_heads").
> Not having the count elevated causes move_pages() to fail on memory
> mapped files coming from xfs.
> 
> Make iomap compatible with the migrate_page_move_mapping() assumption
> by elevating the page count as part of iomap_page_create() and lowering
> it in iomap_page_release().

What are the real-world end-user effects of this bug?

Is a -stable backport warranted?

  parent reply	other threads:[~2018-12-03 23:22 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-15 18:41 p.jaroszynski
2018-11-15 21:07 ` William Kucharski
2018-12-03 23:22 ` Andrew Morton [this message]
2018-12-04  0:38   ` Piotr Jaroszynski

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